(1) Field of the Invention
The present invention relates to a process for the preparation of catalysts. More particularly, the present invention relates to a process for the preparation of catalysts for use in synthesizing methyl formate by dehydrogenating methanol in the gaseous phase.
(2) Description of the Prior Art
Many catalysts are known to be effective for synthesizing methyl formate by dehydrogenating methanol in the gaseous phase. As catalysts having an especially high activity, there can be mentioned catalysts consisting of copper, zirconium and zinc or copper, zirconium, zinc and aluminum (see Japanese Patent Application Laid-Open Specification No. 71008/78) and catalysts consisting of copper oxide, zinc oxide and aluminum oxide (see Japanese Patent Application Laid-Open Specification No. 12315/79).
In these known catalysts, the main component is ordinarily copper, and these catalysts are prepared through a calcination treatment conducted at a high temperature exceeding 400.degree. C. Accordingly, in the case where such catalyst is used after it has been granulated into tablets by the tableting method and packed in a reaction vessel, it is seen that the mechanical strength of the catalyst is drastically reduced in a short time from the initiation of the reaction. The catalyst having a reduced mechanical strength is readily powdered while it is used, and therefore, the pressure difference between the inlet and the outlet of the reaction vessel is increased and there is a risk that the operation is hindered. Accordingly, the above-mentioned known catalysts are still insufficient in the adaptability to the practical operation.